1. Field of the Invention
The present invention relates to an information recording apparatus, an information reproducing apparatus, an information recording method, an information reproducing method, and an optical information recording medium.
2. Description of the Related Art
In the past, disc-shaped optical discs are being widespread used as optical information recording media, and generally, CD (Compact Disc), DVD (Digital Versatile Disc), Blu-Ray Disc (registered trademark, hereinafter also referred to as BD), and the like are being used.
In an optical disc device responding to such optical disc, various information such as various contents of music content, picture content, and the like or various data for computers, and the like are being recorded on the optical disc. In recent years, in particular, larger capacity of the optical disc is being desired with increase in the amount of information due to higher resolution of pictures, higher sound quality of music, and the like, and demand for increase in the number of contents to be recorded on one optical disc.
One method of increasing the capacity of the optical disc is proposed in which information is recorded by interfering light beams of two systems and forming microscopic holograms in the recording medium (see e.g., Japanese Patent Application Laid-Open No. 2006-78834).
A method of enhancing the recording density by stacking the optical discs of the related art into multi-layers (see e.g., I. Ichimura et al, Technical Digest of ISOM'04, pp. 52, October 11-15, Jeju Korea) is being developed as another method of increasing the capacity of the optical disc.